Means for plugging shot-holes.



. No. 806,495. PATENTED DEC. 5, 1905. 0. RASMUSSEN.

MEANS FOR PLUGGING SHOT HOLES.

APPLICATION FILED AUG. 10, 1905.

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MFANS FOR PLUGGING SH@T-HOLE$.

Specification of Letters Patent.

- Patented Dec. 5, 1905.

Application filed August 10, 1905. Serial Ho. 273,830.

To all whom it may concern:

Be itknown that I, OSCAR RnsluussnmaBritish subject, residing at Johannesburg, in the Colony of the Transvaahhave invented certain new and-useful Improvements in Means for Plugging Shot-Holes, of which the following is a specification, reference being bad therein to the accompanying drawings.

The present invention relates to novel means for plugging shot-holes, such as are made in rock or the like for blasting purposes; and the object of the invention is to provide such means as will offer a greater resistance to the explosion-gases than the usualsand or water tamping, and thus enable more material to be broken with a given quantity of explosive than is possible at present. Such means may also be fixedsecurely, even in an extremelytapered hole, in less time than is required to sand-tamp a hole and without the danger concomitant thereto. Generally speaking, such a plug consists of an expausible cylindrical casing adapted to fit into the bore-hole, within which casing fits a wedge member, which in use is caused to present acomparatively large area toward the charge and upon explosion of the latter to be driven into the casing, thereby parts. 5

firmly jamming the entire plug in the hole.

The preferred form of the invention is illustrated by the accompanying drawings, in Which Figure I shows the several parts of the plug separated, and Fig. II the same assembled in a hole ready for use.

In this instance the casing is formed of two sections a and b,whose plane of contact is inclined to the axis, as shown, so that by moving one section relativelyto the other the external diameter of the plug may be increased or diminished, as desired. To further adapt the'plug to fit holes of varying diameter, the sections are made susceptible of a certain amount of spring by cutting grooves 0 0 upon their internal surfaces.

The casing, is shaped out to receive the solid cone d, whose axis coincides with the aforesaid plane of contact between the casing-sections in order to facilitate assembling the ally, so that the face 6 of the section a contiguous to the larger end of the cone is greater in area than the corresponding face f of 6, for

the reason explained hereinafter. The difi'en ence in size of said areas may be increased in effect by beveling off the face f, as shown in Fig. I. A small hole g is formed through the tion.

The cone enters the casing .eccentric-- cone for the passage of the fuse or fuses It, Fig. II. The cone is recessed at the larger end, as at i, for the insertion of the primer.

with a view to its ready insertion into the hole;

but when the primer comes into contact with the charge Z, or otherwise the desired point in the hole is reached, the lower casing memher 6 is thrust forward to expand the plug. The hole is now effectually plugged and the charge may be exploded. The pressure of the gases evolved tends to jam theplug more .firmly into the hole in two Ways: first, by

driving in the cone d, and so spreading apart the halves of the casing, and, secondly, owing to the total pressure on the face a being greater than that on the facef by driving the part a of the casing back over the part b.

It is evident that the form of the device may be varied to a considerable extent while retaining the fundamental idea of the inven- Thus the internal wedge or cone alone may be depended upon,-'the faces 6 and f of the casing members being made substantially equal. while the inclination of their contactplane is retained, or the internal wedge may be formed with flat faces in contact with the correspondingly-modified casing members, or the casing may be made up of more than two sections.

I cla1m as my invention- '1. A plug for shot-holes, comprising an outer casing adapted to be partly expanded by the pressure from the explosion of the shot, and a wedge or cone adapted to be driven into and to further expand said casing by such pressure, substantially as described.

2. The plug forshot-holes, substantially as described with reference to the accompanying drawings; comprising the outer casing made in two sections a and 6 grooved upon their inner surfaces and having inclined contacting surfaces, the facee of the former being greater in area than the face f of the latter; the cone d adapted to slide into and expand said casing and having a hole 9 for the passage of the fuse, and a recess 21 for the insertion of a rimer.

3. A plug for shot-holes comprising an outer casing composed of two sections one of which presents a greater area than the other to the explosive gases, and a wedge or the like adapted to be driven into said casing, substantially as described.

4. A plug for shot-holes comprising an outer casing composed of two sections having their plane of contact inclined with respect to their axis, and a wedge or the like adapted to be driven into said casing, substantially as described.

'5. A plug for shot-holes comprising an outer casing composed of two sections whose plane of contact is inclined with respee to their axis and one of which sections presents to the explosive gases a greater area than the other, and a wedge or the like adapted to be driven into said casing, substantially as described.

6. A plug for shot-holes comprising an outer casing'composed of two sections provided with grooves on their inner faces, and a wedge or the like adapted to be driven into said casing, substantially as described.

. 7. A plug for shot-holes comprising an outer casing composed of two sections having their plane of contact inclined with respect to their axis and provided with grooves on their inner faces, and a wedge or the like adapted to be driven into said casing, substantially as described.

8. A plug for shot-holes comprising an outer casing composed of two sections one of which presents a greater area to the explosive charge than the other and provided with grooves on their inner faces, and a wedge or the like adapted to be driven into said casing, substantially as described.

In testimony whereof I aflix my signature in presence of two witnesses.

OSCAR RASMUSSEN.

Witnesses:

ALFRED LEONARD SPooR, JOSEPH E. KROEFIL. 

